Using Confirmatory Factor Analysis and the Rasch Model to Assess Measurement Invariance in a High Stakes Reading Assessment.

The psychometric properties and multigroup measurement invariance of scores across subgroups, items, and persons on the Reading for Meaning items from the Georgia Criterion Referenced Competency Test (CRCT) were assessed in a sample of 778 seventh-grade students. Specifically, we sought to determine the extent to which score-based inferences on a high stakes state assessment hold across several subgroups within the population of students. To that end, both confirmatory factor analysis (CFA) and Rasch (1980) models were used to assess measurement invariance. Results revealed a unidimensional construct with factorial-level measurement invariance across disability status (students with and without specific learning disabilities), but not across test accommodations (resource guide, read-aloud, and standard administrations). Item-level analysis using the Rasch Model also revealed minimal differential item functioning across disability status, but not accommodation status. [ABSTRACT FROM AUTHOR]